In-Line Fuel Filter Placement ('69 CB350)

jonnymedia

New Member
Hi all. I searched around and haven't not found a difinitive answer on this one. Would really appreciate any tips.


THE SIMPLE QUESTION:
Does it matter where on the fuel line you place an in-line fuel filter. Should it, for example, be below the level of the float bowls, or lower point, or close to the petcock and vertical? If not, can it cause fuel starvation?

THE DETAILED QUESTION:
I was recently told by a shop that my tank is starting to show some rust, just a bit, so to not lose any riding time in the summer, I put on a pair in-line fuel filters with the plan the longer term solution fix over the winter.

As you can see by the photo, I've installed these two filters up close to the petcock. I didn't really put a whole lot of though into where I put them because at the time i didn't think it matter. (And yes, my yellow spark plug wire is usually on the outside of the fuel lines.. just quickly reconnected for photo taking sake).

At any rate, after I put the filters on, I've been experiencing some issues with bogging down at higher RPMs, or if the fuel tanks is not completely full, getting my left side firing at low RPM idle (and as you can see in the photo, that is also the one that is above the float level). I initially didn't put the two and two together, and as I've build this bike up from scratch myself, assumed it was, and doubled checked valve clearances, cleaned carbs, points, etc.

The lightbulb clicked last weekend. The bike runs like a dream on a full tank, but after 80km it starts to bogged down on acceleration, and did stall out. I was close to a gas station, so filled up, turned straight for home (and started to bog down close to home). I know this could also mean carbs or points, but i've re-checked those so many times that I need to find other suspects.

Does anyone have any thoughts on this? I could easily test this by taking out the filters and riding for another 80km, but I'm hoping this is one serious newbie mistake that a few wise words can clear up. Should inline filters be placed at the lowest point (meaning when they're horizontal), or do that just need to be below the float level, OR, does this not matter at all and I'm wandering down the wrong rode.

Much appreciated.

(and sorry for making you tilt your head to view my photo)
 

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jonnymedia said:
Hi all. I searched around and haven't not found a difinitive answer on this one. Would really appreciate any tips.


THE SIMPLE QUESTION:
Does it matter where on the fuel line you place an in-line fuel filter. Should it, for example, be below the level of the float bowls, or lower point, or close to the petcock and vertical? If not, can it cause fuel starvation?

THE DETAILED QUESTION:
I was recently told by a shop that my tank is starting to show some rust, just a bit, so to not lose any riding time in the summer, I put on a pair in-line fuel filters with the plan the longer term solution fix over the winter.

As you can see by the photo, I've installed these two filters up close to the petcock. I didn't really put a whole lot of though into where I put them because at the time i didn't think it matter. (And yes, my yellow spark plug wire is usually on the outside of the fuel lines.. just quickly reconnected for photo taking sake).

At any rate, after I put the filters on, I've been experiencing some issues with bogging down at higher RPMs, or if the fuel tanks is not completely full, getting my left side firing at low RPM idle (and as you can see in the photo, that is also the one that is above the float level). I initially didn't put the two and two together, and as I've build this bike up from scratch myself, assumed it was, and doubled checked valve clearances, cleaned carbs, points, etc.

The lightbulb clicked last weekend. The bike runs like a dream on a full tank, but after 80km it starts to bogged down on acceleration, and did stall out. I was close to a gas station, so filled up, turned straight for home (and started to bog down close to home). I know this could also mean carbs or points, but i've re-checked those so many times that I need to find other suspects.

Does anyone have any thoughts on this? I could easily test this by taking out the filters and riding for another 80km, but I'm hoping this is one serious newbie mistake that a few wise words can clear up. Should inline filters be placed at the lowest point (meaning when they're horizontal), or do that just need to be below the float level, OR, does this not matter at all and I'm wandering down the wrong rode.

Much appreciated.

(and sorry for making you tilt your head to view my photo)

hey there, i'm experiencing a similar issue, on a from-scratch CB350, too. i have my filters on the vertical-up side of the fuel loop. They are clear filters and are not full, which i thought was odd. i tried purging the air from them, and the tank's equalizing tube, but still have problems. did you ever get any feedback on your post? Or resolve your problems? any advice is appreciated. thanks!
 
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